This is a Sources Sought Notice for market research to identify potential contractors capable of providing extensive Systems Engineering and Integration support for strategic weapons systems programs. The work requires a prime contractor with recent, relevant experience managing efforts of similar scope and complexity, with an annual incurred cost of at least $90 million. The period of performance includes a base year from October 1, 2026, to September 30, 2027, with four one-year option periods. Services will be performed in the greater Washington DC area, Cape Canaveral FL, Silverdale WA, Huntsville AL, and Kings Bay GA, requiring approximately 407 full-time equivalent personnel, some needing Top Secret clearance. The notice strongly encourages responses from capable small businesses and provides detailed requirements for submitting a White Paper capability statement.